| 摘要 |
<p>PURPOSE:To compress image data to prescribed data by DCT conversion-processing image data at every block considering a DCT conversion coefficient to be zero data when the counted value of data encoded in a direction from DC and low frequency components toward a high frequency component for a conversion coefficient reaches a prescribed value. CONSTITUTION:A digital picture signal is divided into plural blocks in a DCT processing circuit 1 for respective pieces of picture data in one field and two-dimensional DCT is executed for the respective blocks. The DCT conversion coefficient is quantized in a quantization circuit 2, and the conversion coefficient is converted into sequence from a DC component toward the high frequency component so as output it in a processing circuit 3. Then, it is written into a memory 4. The conversion coefficients of the same frequency component are sequentially read from the low frequency component by signal from a control circuit 5, and they are inputted to an encoding processing circuit 6. The circuit 6 executes a run length encoding processing, and a processing circuit 29 Huffman-encodes the number of the differential bits of the conversion coefficient in the DC component and adds the number of the bits. An encoding data amount from the circuit 29 is compared with a prescribed data amount from a prescribed data amount circuit 10 in a comparison circuit 11. When it exceeds a value, a termination flag is outputted from a picture termination data circuit 8.</p> |
